commit-graph: add '--reachable' option

When writing commit-graph files, it can be convenient to ask for all
reachable commits (starting at the ref set) in the resulting file. This
is particularly helpful when writing to stdin is complicated, such as a
future integration with 'git gc'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-commit-graph.txt b/Documentation/git-commit-graph.txt
index a222cfab08638f5cc43e83f9a982fd0594972f57..dececb79d772447e5ca0d3ea8253f20ea288ddf6 100644 (file)
--- a/Documentation/git-commit-graph.txt
+++ b/Documentation/git-commit-graph.txt
@@ -38,12 +38,16 @@ Write a commit graph file based on the commits found in packfiles.
 +
 With the `--stdin-packs` option, generate the new commit graph by
 walking objects only in the specified pack-indexes. (Cannot be combined
-with --stdin-commits.)
+with `--stdin-commits` or `--reachable`.)
 +
 With the `--stdin-commits` option, generate the new commit graph by
 walking commits starting at the commits specified in stdin as a list
 of OIDs in hex, one OID per line. (Cannot be combined with
---stdin-packs.)
+`--stdin-packs` or `--reachable`.)
++
+With the `--reachable` option, generate the new commit graph by walking
+commits starting at all refs. (Cannot be combined with `--stdin-commits`
+or `--stdin-packs`.)
 +
 With the `--append` option, include all commits that are present in the
 existing commit-graph file.

diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index ea28bc311a24e3d05af4ec3158b677819dd03e9b..c7d0db5ab4b668618720eb30cffad904f0c57b14 100644 (file)
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -10,7 +10,7 @@ static char const * const builtin_commit_graph_usage[] = {
        N_("git commit-graph [--object-dir <objdir>]"),
        N_("git commit-graph read [--object-dir <objdir>]"),
        N_("git commit-graph verify [--object-dir <objdir>]"),
-       N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+       N_("git commit-graph write [--object-dir <objdir>] [--append] [--reachable|--stdin-packs|--stdin-commits]"),
        NULL
 };
 
@@ -25,12 +25,13 @@ static const char * const builtin_commit_graph_read_usage[] = {
 };
 
 static const char * const builtin_commit_graph_write_usage[] = {
-       N_("git commit-graph write [--object-dir <objdir>] [--append] [--stdin-packs|--stdin-commits]"),
+       N_("git commit-graph write [--object-dir <objdir>] [--append] [--reachable|--stdin-packs|--stdin-commits]"),
        NULL
 };
 
 static struct opts_commit_graph {
        const char *obj_dir;
+       int reachable;
        int stdin_packs;
        int stdin_commits;
        int append;
@@ -127,6 +128,8 @@ static int graph_write(int argc, const char **argv)
                OPT_STRING(0, "object-dir", &opts.obj_dir,
                        N_("dir"),
                        N_("The object directory to store the graph")),
+               OPT_BOOL(0, "reachable", &opts.reachable,
+                       N_("start walk at all refs")),
                OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
                        N_("scan pack-indexes listed by stdin for commits")),
                OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
@@ -140,11 +143,16 @@ static int graph_write(int argc, const char **argv)
                             builtin_commit_graph_write_options,
                             builtin_commit_graph_write_usage, 0);
 
-       if (opts.stdin_packs && opts.stdin_commits)
-               die(_("cannot use both --stdin-commits and --stdin-packs"));
+       if (opts.reachable + opts.stdin_packs + opts.stdin_commits > 1)
+               die(_("use at most one of --reachable, --stdin-commits, or --stdin-packs"));
        if (!opts.obj_dir)
                opts.obj_dir = get_object_directory();
 
+       if (opts.reachable) {
+               write_commit_graph_reachable(opts.obj_dir, opts.append);
+               return 0;
+       }
+
        string_list_init(&lines, 0);
        if (opts.stdin_packs || opts.stdin_commits) {
                struct strbuf buf = STRBUF_INIT;

diff --git a/commit-graph.c b/commit-graph.c
index 5b7fa707a5201b8b376463e220cdb53d96f660b8..212232e752a812c7707d174fcf19db5f0eb02010 100644 (file)
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -7,6 +7,7 @@
 #include "packfile.h"
 #include "commit.h"
 #include "object.h"
+#include "refs.h"
 #include "revision.h"
 #include "sha1-lookup.h"
 #include "commit-graph.h"
@@ -656,6 +657,25 @@ static void compute_generation_numbers(struct packed_commit_list* commits)
        }
 }
 
+static int add_ref_to_list(const char *refname,
+                          const struct object_id *oid,
+                          int flags, void *cb_data)
+{
+       struct string_list *list = (struct string_list *)cb_data;
+
+       string_list_append(list, oid_to_hex(oid));
+       return 0;
+}
+
+void write_commit_graph_reachable(const char *obj_dir, int append)
+{
+       struct string_list list;
+
+       string_list_init(&list, 1);
+       for_each_ref(add_ref_to_list, &list);
+       write_commit_graph(obj_dir, NULL, &list, append);
+}
+
 void write_commit_graph(const char *obj_dir,
                        struct string_list *pack_indexes,
                        struct string_list *commit_hex,

diff --git a/commit-graph.h b/commit-graph.h
index a79b8544705d52e8f69c4441dceaa70a549dc720..506cb45fb1178256b2d6c9752c28e300fc0791b2 100644 (file)
--- a/commit-graph.h
+++ b/commit-graph.h
@@ -48,6 +48,7 @@ struct commit_graph {
 
 struct commit_graph *load_commit_graph_one(const char *graph_file);
 
+void write_commit_graph_reachable(const char *obj_dir, int append);
 void write_commit_graph(const char *obj_dir,
                        struct string_list *pack_indexes,
                        struct string_list *commit_hex,

diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index a9e8c774d59bf73205326325e179aaee5c273bb2..2208c266b50766a9300fdcac81be4b695012f1e6 100755 (executable)
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -205,6 +205,16 @@ test_expect_success 'build graph from commits with append' '
 graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
 graph_git_behavior 'append graph, commit 8 vs merge 2' full commits/8 merge/2
 
+test_expect_success 'build graph using --reachable' '
+       cd "$TRASH_DIRECTORY/full" &&
+       git commit-graph write --reachable &&
+       test_path_is_file $objdir/info/commit-graph &&
+       graph_read_expect "11" "large_edges"
+'
+
+graph_git_behavior 'append graph, commit 8 vs merge 1' full commits/8 merge/1
+graph_git_behavior 'append graph, commit 8 vs merge 2' full commits/8 merge/2
+
 test_expect_success 'setup bare repo' '
        cd "$TRASH_DIRECTORY" &&
        git clone --bare --no-local full bare &&